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Google-parent Alphabet’s stock price plunges, erasing more than $500 billion in value

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Kopack, S. (2026, October 29). Google-parent Alphabet’s stock price plunges, erasing more than $500 billion in value. NBC News. https://www.nbcnews.com/business/markets/alphabet-google-stock-ai-advertising-rcna606322

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NBC News · collected 2026-10-29 · by Steve Kopack

Quick Summary

Alphabet's stock price plummeted by up to 15.8% on Thursday, resulting in a loss of over $550 billion in market value and marking its worst single-day drop ever. This decline was triggered by Google’s quarterly financial report, which showed revenue falling short of expectations and lackluster advertising sales, particularly due to the impact of its new AI search feature called “AI Mode.” The company also announced plans for massive spending on AI infrastructure, further contributing to investor anxiety over long-term returns on these investments.
Written by AI on 2026-10-29, from this article's own text only (the story summary below draws on all the coverage).

AI analysis

Story summary

On October 29, 2026, Google's parent company Alphabet saw its stock price plummet by up to 15.8%, resulting in a one-day market value loss of over $500 billion, the worst ever for the company. This drop was largely due to concerns about artificial intelligence (AI) investments not yielding returns quickly enough and fears that AI chatbots might be eating into Google's traditional search business. Despite executives touting more than 1 billion users of its Gemini AI app and promising "promising results" from ad experiments, the market reacted negatively to missed revenue targets and negative cash flow for the second consecutive quarter. This event also affected broader markets, with tech-heavy indexes like the Nasdaq dropping significantly amid a wider reassessment of US economic growth and sustainability in rapid AI spending by major tech companies.

Written for “Tech Stock Sell-off Deepens” on 2026-11-04, grounded in this article and the 25 other(s) covering the same event.

Story

📰 Tech Stock Sell-off Deepens
Economy/Business · 26 article(s) covering the same event. Compare every outlet's account →

Compared with similar articles

This article reads unscored and hedges 0% of its claims. Each row says how that neighbour differs.
The Independent
Hedges 3 of 35 claims Outlet record 59/100
Semafor
Hedges 0 of 5 claims Outlet record 59/100
New York Post
Hedges 1 of 29 claims Outlet record 66/100
CBS News
Hedges 0 of 2 claims Outlet record 65/100
BBC News
Hedges 3 of 23 claims Outlet record 68/100
Semafor
Hedges 0 of 3 claims Outlet record 59/100
CBS News
Hedges 0 of 2 claims Outlet record 65/100
“While both articles describe Alphabet's stock plunge, Article B also mentions an unrelated cryptocurrency hack incident.”
CBS News
Hedges 0 of 3 claims Outlet record 65/100
“The articles describe the same stock drop for Alphabet but include different contexts and additional unrelated events.”
How this article was measured signals, leaning charts, publisher record, byline, topics and claims

Signals How these are calculated →

Claims extracted
17
sentences that state something as happening or true
Uncertain
0%
0 of 17 hedged ("reportedly", "may", "according to")
Leaning
not political
takes no side on a contested political question
Publisher signals
78/100
NBC News's corrections and hedging, across everything collected from it. Not a measure of accuracy.
Outlets on this story
26
Economy/Business
Same framing elsewhere
1
articles that frame the event the way this one does
Analyzed 2026-10-29 · how these are computed

How this is being covered How these are calculated →

Article leaning vs. publisher reliability
Source leaning vs. consistency

Publisher

NBC News · 2088 article(s) · 2 correction(s) detected
Running correction rate · 2 correction(s)

Who wrote this

Steve Kopack
29 article(s) here · 1 carrying a prediction
🔮 “My plan will cut energy prices in half or more than that within 12 months of taking office,” the then-candidate said in September 2024, while adding that it would mean “gasoline below $2 a gallon.”
🔮 Amazon’s spending had already been set to double from 2025.
🔮 Google is still America’s fourth largest company by market value, and its shares are worth more than $3.4 trillion, all told. But the sharp drop in its stock price Thursday was the latest sign of a broader anxiety creeping through Wall Street over how long it will take big artificial intelligence companies to see consistent returns on their massive investments.
🔮 The Federal Reserve is meeting in Washington this week, when it will consider whether to raise interest rates in an effort to tamp down on inflation.
🔮 President Donald Trump, likewise, seemed to back off some of his angrier rhetoric over the weekend, when he told reporters a potential trade deal with Canada would be “settled pretty soon.”
🔮 It is expected to arrive on Tuesday, November 10.
🔮 When Federal Reserve Chairman Kevin Warsh strides onstage in Bangkok on Friday morning, it will be after 11 p.m. on Thursday in New York.
🔮 Friday’s number is the final inflation report before November’s pivotal midterm elections, where business owners and consumers have said they will be voting with their bottom line in mind.
🔮 And the final government inflation report before November’s pivotal midterm elections will likely reflect how much of a headache it’s become for businesses and consumers.
2026-10-13 · assertive framing · What’s fueling inflation? Fuel.
🔮 A move higher in futures markets typically signals that prices will climb in the coming days.
Also by Steve Kopack
Nothing else under this byline is closely related to this article, so these are simply their most recent.
All 29 articles by Steve Kopack →

Topics

Alphabet America Caterpillar Google Nvidia

Subjects

Alphabet ORG · 6× Google ORG · 4× Caterpillar ORG · 3× America GPE · 1× JPMorgan Chase ORG · 1× Microsoft ORG · 1× Nvidia ORG · 1× Philadelphia GPE · 1× Philipp Schindler PERSON · 1× The S&P 500 ORG · 1×

Narrative

The company is working on addressing this, senior vice president Philipp Schindler said on the investor call, adding that “ad experiments” in the feature have “shown promising results” Company executives tried to soften the blow for investors by touting more than 1 billion users of its Gemini AI app. But all that AI is coming at a massive cost to Alphabet, which disclosed that it has committed to more than $1 trillion worth of multi-year spending agreements to fund the infrastructure, energy and leases required to run AI systems.
framing: assertive · carried by 1 article(s) · first seen 2026-10-29
🔮 Google is still America’s fourth largest company by market value, and its shares are worth more than $3.4 trillion, all told. But the sharp drop in its stock price Thursday was the latest sign of a broader anxiety creeping through Wall Street over how long it will take big artificial intelligence companies to see consistent returns on their massive investments.

Claims (17 extracted, 0 hedged)

Shares of Google parent company Alphabet sank on Thursday by as much as 15.8%, putting the company on course for its worst single-day drop in history. asserted
Shares → sink → history
The plunge also instantly wiped out more than $550 billion in market capitalization, also ranking as the company’s worst one day market value loss ever. asserted
plunge → wipe → loss
It also ranks as the second-worst wipeout in market history, only behind Nvidia’s $589 billion drop in 2025. asserted
It → rank → 2025
Google is still America’s fourth largest company by market value, and its shares are worth more than $3.4 trillion, all told. But the sharp drop in its stock price Thursday was the latest sign of a broader anxiety creeping through Wall Street over how long it will take big artificial intelligence companies to see consistent returns on their massive investments. asserted
it → tell → investments
The significant selling came after the company reported its latest quarterly financials Wednesday, revealing that revenues fell short of Wall Street expectations. asserted
revenues → come → expectations
It also reported lackluster advertising sales. asserted
It → report → sales
The “magnitude” of the slowdown in Google’s search business was “steeper than expected,” JPMorgan Chase analysts wrote in a Thursday morning note. asserted
analysts → expect → note
A senior Alphabet executive told investors Wednesday that part of the reason ad revenues from search were underperforming was because of Google’s own “AI Mode” search feature, which was resulting in fewer ads. asserted
which → tell → ads
The company is working on addressing this, senior vice president Philipp Schindler said on the investor call, adding that “ad experiments” in the feature have “shown promising results” Company executives tried to soften the blow for investors by touting more than 1 billion users of its Gemini AI app. But all that AI is coming at a massive cost to Alphabet, which disclosed that it has committed to more than $1 trillion worth of multi-year spending agreements to fund the infrastructure, energy and leases required to run AI systems. asserted
it → work → systems
The company said during its July earnings report that it planned to spend more than $200 billion this year, which is double what it spent in 2025. asserted
it → say → 2025
The company in June also raised almost $80 billion in capital, also to spend on the ever-expanding AI buildout. asserted
company → raise → buildout
Alphabet’s disappointing results also came against the backdrop of better results from its peer Microsoft, whose shares initially rose in after market trading Wednesday and overnight, before reversing course to fall about 2% by 10:50 a.m. ET Thursday. asserted
shares → come → ET
The big drop in Alphabet shares dragged down the Nasdaq Composite index, which was down 1.6% by mid-morning. asserted
which → drag → morning
The S&P 500 fell slightly less, by about 0.6%. asserted
S&P → fall → %
Stock in the chip companies that supply equipment for AI data centers followed Alphabet shares lower, with the Philadelphia semiconductor index dropping 1.6%. asserted
index → supply → shares
The bleeding even spread beyond the tech sector, as shares of construction equipment giant Caterpillar — a key supplier of the machines required to build data centers — plunged 9% early Thursday. Caterpillar’s recent earnings report revealed that the company’s revenues beat Wall Street expectations, but by less than many traders had hoped. asserted
traders → spread → less
As investors clamor for ever-higher returns from companies linked to the costly AI buildout, stock in firms that only narrowly top earnings targets, like Caterpillar, have been punished with dramatic sell-offs. asserted
that → clamor → offs
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